[net-next 03/13] igb: Update max_frame_size to account for an optional VLAN tag if present

Jeff Kirsher
2011-09-17T08:04:42Z

From: Alexander Duyck <alexander.h.duyck@intel.com>

This patch modifies the max_frame_size in order account for an optional
VLAN tag. In order to support this we must also increase the
MAX_STD_JUMBO_FRAME_SIZE to account for the 4 extra bytes.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---
drivers/net/ethernet/intel/igb/igb.h | 2 --
drivers/net/ethernet/intel/igb/igb_main.c | 19 ++++++++++++-------
2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/intel/igb/igb.h b/drivers/net/ethernet/intel/igb/igb.h
index 577fd3e..8e90b85 100644
--- a/drivers/net/ethernet/intel/igb/igb.h
+++ b/drivers/net/ethernet/intel/igb/igb.h
@@ -117,8 +117,6 @@ struct vf_data_storage {
#define IGB_RXBUFFER_2048 2048
#define IGB_RXBUFFER_16384 16384

-#define MAX_STD_JUMBO_FRAME_SIZE 9234
-
/* How many Tx Descriptors do we need to call netif_wake_queue ? */
#define IGB_TX_QUEUE_WAKE 16
/* How many Rx Buffers do we bundle into one write to the hardware ? */
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index aa78c10..6156275 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -2396,7 +2396,8 @@ static int __devinit igb_sw_init(struct igb_adapter *adapter)
adapter->rx_itr_setting = IGB_DEFAULT_ITR;
adapter->tx_itr_setting = IGB_DEFAULT_ITR;

- adapter->max_frame_size = netdev->mtu + ETH_HLEN + ETH_FCS_LEN;
+ adapter->max_frame_size = netdev->mtu + ETH_HLEN + ETH_FCS_LEN +
+ VLAN_HLEN;
adapter->min_frame_size = ETH_ZLEN + ETH_FCS_LEN;

spin_lock_init(&adapter->stats64_lock);
@@ -2962,16 +2963,19 @@ static inline int igb_set_vf_rlpml(struct igb_adapter *adapter, int size,
**/
static void igb_rlpml_set(struct igb_adapter *adapter)
{
- u32 max_frame_size;
+ u32 max_frame_size = adapter->max_frame_size;
struct e1000_hw *hw = &adapter->hw;
u16 pf_id = adapter->vfs_allocated_count;

- max_frame_size = adapter->max_frame_size + VLAN_TAG_SIZE;
-
- /* if vfs are enabled we set RLPML to the largest possible request
- * size and set the VMOLR RLPML to the size we need */
if (pf_id) {
igb_set_vf_rlpml(adapter, max_frame_size, pf_id);
+ /*
+ * If we're in VMDQ or SR-IOV mode, then set global RLPML
+ * to our max jumbo frame size, in case we need to enable
+ * jumbo frames on one of the rings later.
+ * This will not pass over-length frames into the default
+ * queue because it's gated by the VMOLR.RLPML.
+ */
max_frame_size = MAX_JUMBO_FRAME_SIZE;
}

@@ -4461,7 +4465,7 @@ static int igb_change_mtu(struct net_device *netdev, int new_mtu)
{
struct igb_adapter *adapter = netdev_priv(netdev);
struct pci_dev *pdev = adapter->pdev;
- int max_frame = new_mtu + ETH_HLEN + ETH_FCS_LEN;
+ int max_frame = new_mtu + ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN;
u32 rx_buffer_len, i;

if ((new_mtu < 68) || (max_frame > MAX_JUMBO_FRAME_SIZE)) {
@@ -4469,6 +4473,7 @@ static int igb_change_mtu(struct net_device *netdev, int new_mtu)
return -EINVAL;
}

+#define MAX_STD_JUMBO_FRAME_SIZE 9238
if (max_frame > MAX_STD_JUMBO_FRAME_SIZE) {
dev_err(&pdev->dev, "MTU > 9216 not supported.\n");
return -EINVAL;
--
1.7.6